1. Field of the Invention
The present invention relates to an electric stapler.
2. Related Art
Conventionally, an electric stapler is known which is placed at a sheet conveying path inside a copier or a printer for binding a plurality of sheets of paper that have been copied or printed.
In one of the conventional electric staplers, a straight-shaped staple is formed into a U-shape by a forming plate and then the staple formed into the U-shape is driven into sheets by a driver member (see, for example, Patent Document 1: JP-B2-3620351).
In one of the conventional electric staplers, a clincher mechanism is provided at a position opposing to a driver mechanism in which a forming plate or a driver member is accommodated and a staple is driven into sheets in a state where the sheets are clamped between the driver mechanism and the clincher mechanism. Here, legs of the staple driven and penetrating through the sheets are bent along a clincher groove of the clincher mechanism, thereby binding the sheets (see, for example, Patent Document 2: JP-A-2005-335021).
In one of the conventional electric staplers, when sheets are clamped between a driver mechanism and a clincher mechanism, a mechanism (spring, etc.) for adjusting a difference in a thickness of the sheets is provided. For example, Patent Document 3 (JP-Y2-2561157) discloses a configuration in which a paper thickness adjustment spring is provided to a driver link.
In one of the conventional electric staplers, a mechanism for detecting a presence or absence of staples is provided. For example, Patent Document 4 (JP-B2-4103700) discloses a configuration in which a detection sensor for detecting the presence or absence of staples and outputting a detected signal is provided at a frame that supports a magazine. In the configuration, a flag member which is disposed to face the detection sensor when the electric stapler is in the inactive condition and activates to allow the detection sensor to detect the presence or absence of staples is provided at the magazine. A detection member which is disposed to enter into the connected staples loading space of a cartridge and activated by the connected staples loaded in the cartridge is provided on the cartridge. A cooperation member is provided between the detection member and the flag member to operate the detection member in cooperation with the flag member in a state where the cartridge is mounted on the magazine.
According to the structure of Patent Document 3, since the paper thickness adjustment spring is provided to the driver link, a load of the spring is always applied even in a state where the sheets are not clamped (a stand-by state where the staple is not driven). Accordingly, there is a problem that a magazine urged by the spring is swung and thus slanted or a guide groove is worn.
Further, if the flag member is provided at the magazine as disclosed in Patent Document 4, there is a problem that the flag member is deviated from a detecting area of the sensor due to the slant of the magazine and thus the detection of the presence or absence of staples does not work properly.